Device for heating and drying a material web by suspension in a tunnel



Dec; 23. 1969 A. HUTZENLAUB DEVICE FOR HEATING AND DRYING A MATERIAL WEBBY SUSPENSION IN A TUNNEL 2 Sheets-Sheet l Filed'July 14, 1967 FIG. 4

Dec. 23. 1969 A. HUTZENLAUB 3,485,429

DEVICE FOR HEATING AND DRYING A MATERIAL WEB BY SUSPENSION IN A TUNNELFiled July 14, 1967 v 2 Sheets-Sheet 2 wvmrm \HRM/N HurZE/VL nus UnitedStates Patent Int. Cl. B65h 17/32 US. Cl. 226-97 Claims ABSTRACT OF THEDISCLOSURE A process and device for heating and drying a material Web bysuspension in a tunnel with air nozzle assemblies arranged and designedin a way to produce air cushions causing the material web to float in anundulatory line. The air nozzle assemblies provided with lateraltangential flow of air preventing the material web from flapping beforeand after passing over the air nozzle assemblies.

Background of the invention The invention relates to a tunnel whereinthe material Web is kept in suspension by air.

Tunnels of this general type have been used in the past but all havebeen subject to certain disadvantages. Such tunnels are conventionallyprovided with nozzles spaced relatively wide apart from another so thatthe running material web is subject to flapping.

Summary of the invention According to the present invention a process isperformed by means of a tunnel provided with closely spaced air nozzleson individual air nozzle assemblies, These assemblies commonly form atunnel in form of an undulatory line. These assemblies further havelateral guide plates forcing a tangential flow of air against thematerial Web, in this way stabilizing the running of the material andpreventing disturbing air turbulances.

Brief description of the drawing According to the invention illustratedin FIGS. 1 and 2 of the drawing, the tunnel 1 is provided with airnozzle assemblies arranged therein and the undulatory material 2 webtransport and guide route is limited by the air nozzle assemblies.Further the air nozzle assemblies are arranged consecutively and the airnozzles 4 of every assembly are essentially adjacent to the air nozzles4 of neighbouring air nozzle assemblies. The bore hole of each nozzle 4is, as illustrated in FIG. 4, wider facing to the material web 2 thanfacing away from same.

In FIG. 3 the air nozzle assemblies 3 are arranged adjacent the counternozzle assemblies 7.

FIG. 1 and FIG. 2 illustrate alternative solutions in which the nozzleassemblies 3 above the material web commonly form a convex curve andthose of the individual counter air nozzle assemblies 7 commonly form aconcave curve or vice versa.

FIG. 3 illustrates also a device wherein the radius of the convex orconcave curves of the air nozzle assem- 7 3,485,429 Patented Dec. 23,1969 blies 3 and 7 above and below the material web 2 is very large, oralmost infinite radius.

FIG. 4 illustrates one nozzle 4 the use of which represents an excellentadvantage for all designs illustrated. The bore hole of such a nozzleillustrated in FIG, 4 is wider (at 5) facing to the material Web 2 thanfacing away from it (at 6). In FIG. 4 the numeral 8 indicates the 'wallof an air nozzle assembly showing one nozzle 4 only but composing manynozzles 4.

Description of the preferred embodiment FIG. 5 illustrates the onenozzle assembly. From the sides of the air nozzle assembly, supportingair 11 flows in tangential direction against the material web section 2.The sides of the air nozzle assemblies have guide plates 9 each forming,in combination with the Web 2, slotted nozzles 10. The guide plates 9are curved in the same sense as that section of the material runningalong them. The narrowest cross-section of the space between guide plate9 and concave face of the material web is located between both ends ofthe guide plate 9.

From the above description it will be clear that the nozzles arearranged so that they are equally spaced from the web 2 and the tips ofthe nozzles define a surface parallel to the path of the web. Thus, eachnozzle exerts the same influence on the material by providing a cushionof air paralleling the path of the web by static pressure rather than byvelocity impact.

The counterbore or enlargement 5 at the outer end of each nozzle has theeffect of reducing the speed of the air to convert its velocity pressureinto static pressure and thus provide an efiicient cushion for the webwithout applying concentrated jet pressures to the material.

I claim:

1. An apparatus for supporting and guiding a web of material through amaterial treating tunnel as it passes along a predetermined essentiallyelongated sinusoidal path, comprising a plurality of support assembliesconsecutively arranged on respectively opposite sides of said path instaggered relation, the assemblies on at least one side of said pathcomprising nozzle assemblies, each including a plurality of individualnozzles respectively having a mouth for directing air essentiallytransversely of said path, means for sup-plying air to said nozzleassemblies, the mouths of the individual nozzles of each assembly beingarranged in a surface the profile of which, in direction of movement ofsaid web of material, is arcuateLy convex, and means fixed relative toeach of said nozzle assemblies and spaced from the nozzles thereof on.opposite sides of each. nozzle assembly in the direction of said path,said means being arranged transverse to said path to be disposedsubstantially adjacent the web to confine air to flow along said pathclosely adjacent the web whereby the web of material is positioned andguided by an air cushion on the one side thereof along said sinusoidalpath.

2. Apparatus according to claim 1 wherein each of said assemblies isprovided with further nozzles, at the leading and trailing edgesthereof, arranged to direct jets of air adjacent and longitudinally ofsaid path.

3. Apparatus according to claim 2 wherein said means comprises platescarried by each of said assemblies to extend generally along said pathoutwardly of said fur- 3 4 ther nozzles and curved in the same sense assaid profile 2,393,243 1/1946 Franz 34-156 X of said surface. 2,682,1166/1954 Dungler 34156 X 4. Apparatus according to claim 1 wherein thedis- 3,097,971 7/1963 Carlisle et al. 341S6 X charge end of each nozzlecomprises a central passageway 3,283,920 11/1966 Schonfelder et al.302--29 X and an enlarged counterbore into which said passagewaydischarges its air to reduce the velocity thereof. FOREIGN PATENTS 5.Apparatus according to claim 1 wherein said means comprises asubstantially rigid plate secured to the op- 940'881 11/1963 GreatBummposlte sldes of each nozzle aSsemb1 y' EDWARD G. FAVORS, PrimaryExaminer References Cited 10 UNITED STATES PATENTS US. Cl. X.R.

602,799 4/1898 Burns 34156 34-10, 57, 156

